/*
 * Copyright 1999-2017 Alibaba Group Holding Ltd.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.alibaba.polardbx.druid.sql.dialect.mysql.ast.clause;

import com.alibaba.polardbx.druid.sql.ast.SQLExpr;
import com.alibaba.polardbx.druid.sql.ast.SQLObject;
import com.alibaba.polardbx.druid.sql.ast.SQLStatement;
import com.alibaba.polardbx.druid.sql.ast.SqlType;
import com.alibaba.polardbx.druid.sql.ast.statement.SQLIfStatement;
import com.alibaba.polardbx.druid.sql.dialect.mysql.ast.MySqlObjectImpl;
import com.alibaba.polardbx.druid.sql.dialect.mysql.ast.statement.MySqlStatementImpl;
import com.alibaba.polardbx.druid.sql.dialect.mysql.visitor.MySqlASTVisitor;

import java.util.ArrayList;
import java.util.List;

/**
 * @author zz [455910092@qq.com]
 */
public class MySqlCaseStatement extends MySqlStatementImpl {

    //case expr
    private SQLExpr condition;
    //when statement list
    private List<MySqlWhenStatement> whenList = new ArrayList<MySqlWhenStatement>();
    //else statement
    private SQLIfStatement.Else elseItem;

    public SQLExpr getCondition() {
        return condition;
    }

    public void setCondition(SQLExpr condition) {
        this.condition = condition;
    }

    public List<MySqlWhenStatement> getWhenList() {
        return whenList;
    }

    public void setWhenList(List<MySqlWhenStatement> whenList) {
        this.whenList = whenList;
    }

    public void addWhenStatement(MySqlWhenStatement stmt) {
        this.whenList.add(stmt);
    }

    public SQLIfStatement.Else getElseItem() {
        return elseItem;
    }

    public void setElseItem(SQLIfStatement.Else elseItem) {
        this.elseItem = elseItem;
    }

    @Override
    public void accept0(MySqlASTVisitor visitor) {
        if (visitor.visit(this)) {
            acceptChild(visitor, condition);
            acceptChild(visitor, whenList);
            acceptChild(visitor, elseItem);
        }
        visitor.endVisit(this);
    }

    @Override
    public List<SQLObject> getChildren() {
        List<SQLObject> children = new ArrayList<SQLObject>(whenList);
        if (elseItem != null) {
            children.add(elseItem);
        }
        return children;
    }

    /**
     * case when statement
     *
     * @author zz
     */
    public static class MySqlWhenStatement extends MySqlObjectImpl {

        private SQLExpr condition;
        private List<SQLStatement> statements = new ArrayList<SQLStatement>();

        @Override
        public void accept0(MySqlASTVisitor visitor) {
            if (visitor.visit(this)) {
                acceptChild(visitor, condition);
                acceptChild(visitor, statements);
            }
            visitor.endVisit(this);
        }

        public SQLExpr getCondition() {
            return condition;
        }

        public void setCondition(SQLExpr condition) {
            this.condition = condition;
        }

        public List<SQLStatement> getStatements() {
            return statements;
        }

        public void setStatements(List<SQLStatement> statements) {
            this.statements = statements;
        }

    }

    @Override
    public SqlType getSqlType() {
        return null;
    }
}
